mute-new.sikuli

(Download this script)
setAutoWaitTimeout(5)

def dragLeft(t):
  dragDrop(t,  t.getCenter().left(200))

sys = App.open("System Preferences.app")
with Region(sys.window()):
        click()
        click()
        thumbs = findAll()
        for t in list(thumbs)[:2]: # only take the first two 
          dragLeft(t) # off